Commitments and Contingencies Available Lines of Credit, Outstanding Standby Letter of Credits, and Bonds (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	$ 660,000
Credit Facility [Member]
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	660,000	[1]	660,000	[1]
Long-term borrowings	(95,000)	[1]	(120,000)	[1]
Standby LOCs issued and outstanding	(47,336)	[1]	(49,491)	[1]
Net available for additional borrowings and LOCs	517,664	[1]	490,509	[1]
Unsecured Multicurrency Revolving Lines of Credit [Member]
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	127,181		115,269
Standby LOCs issued and outstanding	(32,882)		(31,714)
Net available for additional borrowings and LOCs	92,241		79,303
Short-term borrowings(2)	(2,058)	[2]	(4,252)	[2]
Surety Bond [Member]
Line of Credit Facility [Line Items]
Unsecured surety bonds in force	$ 145,292		$ 186,446

[1] Refer to Note 6 for details regarding our secured credit facilities.

[2] Short-term borrowings are included in "Other current liabilities" on the Consolidated Balance Sheets.